In a known control system of this kind (published German patent application DE-OS No. 32 34 345), for the machining of workpieces, mobile control modules, as information carriers with programmable memories, are secured to workpieces or workpiece carriers. The information stored there can be read out in a contactless manner by means of stationary control modules, as so-called reading and writing stations in the vicinity of the production line from the mobile control modules. With the known system, it is also possible to perform an exchange of information between the mobile and stationary control modules on the transport line, in such a manner that as machining of the workpieces progresses, the machining status at a given time is recorded in a memory block of the mobile control module associated with the workpiece, and this machining status can then be read out by the stationary control module past which the mobile control module passes later. The stationary control modules of the reading and writing stations are connected for production control with a central control point, in which the information is processed as it is received, and both the routes and the machining sequence of the individual workpieces in the production line are controlled. For identification of each workpiece, the workpiece carrier is provided with an identity datum recorded permanently in its mobile control module, and this datum is detected at the various reading stations as soon as the workpiece carrier moves past them. In this manner, the central control point can monitor and control the route of each workpiece carrier.
Such arrangements have the disadvantage, however, that for the central control point, the electronics necessary for all the data management as well as for controlling and monitoring the various workpieces and the individual production and routing stations is very expensive. If a plurality of workpiece carriers are in transit on the production line, then various mobile control modules may arrive at various reading stations at the same time, so that the exchange of information and the processing of information by the central control is no longer assured. Furthermore, the sequence of production can be ruined, for example by the removal of one workpiece carrier from the production line at one point and its reinsertion at some other point, because the position of the workpiece carrier registered in the central control point then no longer agrees with the actual position. The changes must then be corrected by making a manual intervention at the central control point.